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Benjamin Smith

Principal Physicist

Affiliate Associate Professor, Earth and Space Sciences





Department Affiliation

Polar Science Center


B.S. Physics, University of Chicago, 1997

M.S. Geology & Geophysics, University of Wisconsin - Madison, 1999

Ph.D. Earth & Space Sciences/Geophysics, University of Washington - Seattle, 2005


2000-present and while at APL-UW

Comparisons of satellite and airborne altimetry with ground-based data from the interior of the Antarctic ice sheet

Brunt, K.M., B.E. Smith, T.C. Sutterly, N.T. Kurtz, and T.A. Neumann, "Comparisons of satellite and airborne altimetry with ground-based data from the interior of the Antarctic ice sheet," Geophys. Res. Lett., 48, doi:10.1029/2020GL090572, 2021.

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28 Jan 2021

A series of traverses has been conducted for validation of the National Aeronautics and Space Administration Ice, Cloud, and land Elevation Satellite 2 (ICESat‐2) on the flat interior of the Antarctic ice sheet. Global Navigation Satellite System data collected on three separate 88S Traverses intersect 20% of the ICESat‐2 reference ground tracks and have precisions of better than ±7 cm and biases of less than ~4 cm. Data from these traverses were used to assess heights from ICESat‐2, CryoSat‐2, and Airborne Topographic Mapper (ATM). ICESat‐2 heights have better than ±3.3 cm bias and better than ±7.2 cm precision. ATM heights have better than 9.3 cm bias and better than ±9.6 cm precision. CryoSat‐2 heights have –38.9 cm of bias and ±47.3 cm precision. These best case results are from the flat ice‐sheet interior but provide a characterization of the quality of satellite and airborne altimetry.

Brief communication: Heterogenous thinning and subglacial lake activity on Thwaites Glacier, West Antarctica

Hoffman, A.O., K. Christianson, D. Shapero, B.E. Smith, and I. Joughin, "Brief communication: Heterogenous thinning and subglacial lake activity on Thwaites Glacier, West Antarctica," Cryosphere, 14, 4603-4609, doi:10.5194/tc-14-4603-2020, 2020.

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18 Dec 2020

A system of subglacial lakes drained on Thwaites Glacier from 2012-2014. To improve coverage for subsequent drainage events, we extended the elevation and icevelocity time series on Thwaites Glacier through austral winter 2019. These new observations document a second drainage cycle in 2017/18 and identified two new lake systems located in the western tributaries of Thwaites and Haynes glaciers. In situ and satellite velocity observations show temporary < 3% speed fluctuations associated with lake drainages. In agreement with previous studies, these observations suggest that active subglacial hydrology has little influence on thinning and retreat of Thwaites Glacier on decadal to centennial timescales.

Pervasive ice sheet mass loss reflects competing ocean and atmosphere processes

Smith, B., and 14 others, "Pervasive ice sheet mass loss reflects competing ocean and atmosphere processes," Science, 368, 1239-1242, doi:10.1126/science.aaz5845, 2020.

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12 Jun 2020

Quantifying changes in Earth's ice sheets, and identifying the climate drivers, is central to improving sea-level projections. We provide unified estimates of grounded and floating ice mass change from 2003 to 2019 using NASA's ICESat and ICESat-2 satellite laser altimetry. Our data reveal patterns likely linked to competing climate processes: Ice loss from coastal Greenland (increased surface melt), Antarctic ice shelves (increased ocean melting), and Greenland and Antarctic outlet glaciers (dynamic response to ocean melting), was partially compensated by mass gains over ice sheet interiors (increased snow accumulation). Losses outpaced gains, with grounded-ice loss from Greenland (200 Gt a–1) and Antarctica (118 Gt a–1) contributing 14 mm to sea level. Mass lost from West Antarctica's ice shelves accounted for over 30% of that region's total.

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In The News

Shrinking ice sheets lifted global sea level 14 millimeters

Eos (American Geophysical Union), Tim Hornyak

Researchers measure both grounded and floating ice sheets using satellite data spanning a 16-year period.

15 May 2020

NASA: 318 gigatons of ice are melting in Antarctica and Greenland each year

Tech Times, Giuliano J.

The results of a new study reveal that the ice sheet in Antarctica's interior is getting thicker because of increased snowfall. However, the warming of the ocean has also caused ice meltdowns in the Antarctic Peninsula and West Antarctica, which outweigh the gains in the interior.

3 May 2020

NASA space lasers offer 'fantastically detailed' look at the world's ice loss

Gizmodo, Yessenia Funes

A new study shows increased snow accumulation isn’t enough to offset massive ice losses in Greenland and Antarctica. Greenland has shed an average of 200 gigatons of ice a year, and Antarctica has lost an average of 118 gigatons of ice a year. That's contributed to more than half an inch of sea level rise over the past 16 years alone

2 May 2020

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